CHICAGO: ’Tis the season — for heart attacks? Not to dampen any spirits, but studies show heart troubles spike this time of year.

It’s not just a Western phenomenon; recent research in China found the same thing. The increase includes fatal and nonfatal heart attacks and a less serious condition dubbed “holiday heart syndrome” — an irregular heartbeat caused by too much booze.

Reasons for the seasonal increase are uncertain. Theories include cold weather, overindulgence and stress.

“The other day we had three heart attacks come in within four hours,” said Dr. Charles Davidson, chief of Northwestern Memorial Hospital’s cardiac catheterization services. The hospital’s usual rate is two or three a week.

American Heart Association spokesman Dr. Richard Stein, a cardiologist at New York University’s medical center, said most studies investigating holiday heart trends have found a statistical increase in heart attacks and other problems — not a giant surge but worth noting just the same.

It happens in cold climates, sometimes when sedentary people or those with heart disease take on too much snow shoveling, or spend too much time outdoors. Cold weather can constrict arteries, increasing demand on the heart, he said, But it also happens in warm places. Flu season coincides with winter holidays and Stein said that might be a factor since the virus can cause inflammation that also can stress the heart.

David Phillips, a sociologist at the University of California’s San Diego campus, has long studied when people die. His research, based on millions of death certificates nationwide, shows that cardiac deaths including fatal heart attacks increase almost 5 percent on Christmas Day, the day after and on New Year’s Day. Deaths from other causes also increase at holiday time, but not as much, he has found.

Phillips estimates that there are 2,000 extra deaths each year, mostly from heart-related problems, linked with Christmas and New Year’s. He says hospitals’ holiday staffing is a factor, with fewer doctors and nurses working and the most senior employees often on vacation.

Also, he said, in the rush leading up to the holidays, people tend to ignore symptoms and put off going to the doctor — which can be dangerous if heart problems or other serious illnesses are brewing.

His advice? Head to the emergency room with life-threatening symptoms such as chest pain, unexplained falls, numbness or tingling. But for non-emergencies and elective surgeries, you might want to consider holding off until hospital staffing is back to normal.

Stress of holidays

Nashville dentist Jason Cabler fell victim last year. After opening presents on Christmas morning with his wife and two teens, Cabler headed downstairs to lift weights in his basement gym when he started to feel a little odd, including tightness in his chest.

“I said, ‘I’m just having an off day, I’ll just work through it,’ ” he recalled. But when his symptoms got worse, he climbed upstairs and asked his son to drive him to the hospital. Ten minutes later, he was in a hospital emergency room. Doctors diagnosed a heart attack and implanted two stents to open a blocked artery.

Cabler was just 45, had always been healthy and active, so the diagnosis was a surprise. Now he says the stress of running around buying gifts and braving holiday crowds might have been a factor. Doctors also found he had high cholesterol and triglycerides, prescribed medicine and recommended cutting down on fat and sugar.

Cabler said he’s trying to cut the stress this holiday season — buying fewer gifts and spending more time at home.

“We’re keeping it a little more low-key,” he said.

Then there’s “holiday heart syndrome,” a type of irregular heartbeat called atrial fibrillation brought on by too much alcohol.

It involves irregular contractions in the heart’s upper two chambers that patients often feel as palpitations, a funny fluttery sensation in the chest, or chest pain. It’s like the heart’s rhythm has gone “haywire,” according to a report last year in the Harvard Heart Letter.

The condition typically happens in otherwise healthy adults, and resolves within 24 hours.